HELENA, Ala. (AP) — For the second time in two months, a pipeline that supplies gasoline to millions of people was shut down, raising the specter of another round of gas shortages and price increases.

The disruption occurred when a track hoe — a machine used to remove dirt — struck the pipeline, ignited gasoline and caused an explosion Monday that sent flames and thick black smoke soaring over a forest in northern Alabama, Colonial Pipeline said. One worker was killed and five were injured.

A September leak that spilled 252,000 to 336,000 gallons of gasoline occurred not far from the location of Monday's explosion. That leak led to days of dry pumps and higher gas prices in Alabama, Georgia, Tennessee and the Carolinas while repairs were made.

The cause of the leak still has not been determined, and the effects of the latest disruption weren't immediately clear.

Colonial Pipeline, based in Alpharetta, Georgia, operates 5,599 miles of pipelines, transporting more than 100 million gallons daily of gasoline, jet fuel, home heating oil and other hazardous liquids in 13 states and the District of Columbia, according to company filings. Authorities have not said which type of fuel was involved in the explosion Monday.

Plagued by a severe drought after weeks without rain, the section of the state where the explosion happened has been scarred by multiple wildfires in recent weeks, and crews worked to keep the blaze from spreading.

Coleen Vansant, a spokeswoman with the Alabama Forestry Commission, said crews built a 75-foot-long earthen dam to contain burning fuel. The Shelby County Sheriff's Office said the blaze had been contained but it was unclear how long the fire may take to burn out.

Two wildfires caused by the explosion burned 31 acres of land, Vansant said.

"We'll just hope and pray for the best," Gov. Robert Bentley said in a statement.

Houses around the blast scene were evacuated, and sheriff's Capt. Jeff Hartley said it wasn't clear when people might be able to return home.

Eight or nine subcontractors were working on the pipeline when it exploded about 3 p.m. Monday, sheriff's Maj. Ken Burchfield told Al.com. The conditions of those hurt weren't immediately known.

"Colonial's top priorities are the health and safety of the work crew on site and protection of the public," the company said in a brief statement.

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